USB stick is no longer recognized, why?

I've had a USB stick (Emtec, 32 GB) for about two years, which worked fine so far,

both on a Macbook (OS Sierra10.12.6) and on a Windows7 laptop.

The other day I used it on the Mac, everything went fine, I clicked in between in a second open window, which was also always easy, and now this window with the click to the stick was gone and the symbol for the stick was not displayed more, he was simply no longer existent for the system!

So I pulled it from the Mac (the normal ejection was not even possible), put it back as a test: nothing!

Even after turning off the Mac, the stick was virtually dead.

Also on the Akoya Windows7.

What is behind it, can this be repaired?

It was important data on it!

That sounds like a defective USB stick.

If he is no longer recognized on any PC, you will not be able to do much there.

Can you speak to him somewhere, then you can try EaseUs.

https://www.easeus.de/speichermedien-wiederherstellen/usb-speicherstick-wiederherstellen.html

For the future: USB sticks are NOT suitable for securing important data.